Fine-tuning favors mixed axion/axino cold dark matter over neutralinos in the minimal supergravity model

Over almost all of minimal supergravity (mSUGRA or CMSSM) model parameter space, there is a large overabundance of neutralino cold dark matter (CDM). We find that the allowed regions of mSUGRA parameter space which match the measured abundance of CDM in the universe are highly fine-tuned. If instead we invoke the Peccei-Quinn-Weinberg-Wilczek solution to the strong CP problem, then the SUSY CDM may consist of an axion/axino admixture with an axino mass of order the MeV scale, and where mixed axion/axino or mainly axion CDM seems preferred. In this case, fine-tuning of the relic density is typically much lower, showing that axion/axino CDM (a\tilde{a}CDM) is to be preferred in the paradigm model for SUSY phenomenology. For mSUGRA with a\tilde{a}CDM, quite different regions of parameter space are now DM-favored as compared to the case of neutralino DM. Thus, rather different SUSY signatures are expected at the LHC in the case of mSUGRA with a\tilde{a}CDM, as compared to mSUGRA with neutralino CDM.Comment: 23 pages with 17 .eps figure

Threshold and Flavour Effects in the Renormalization Group Equations of the MSSM I: Dimensionless Couplings

In a theory with broken supersymmetry, gaugino couplings renormalize differently from gauge couplings, as do higgsino couplings from Higgs boson couplings. As a result, we expect the gauge (Higgs boson) couplings and the corresponding gaugino (higgsino) couplings to evolve to different values under renormalization group evolution. We re-examine the renormalization group equations (RGEs) for these couplings in the Minimal Supersymmetric Standard Model (MSSM). To include threshold effects, we calculate the $\beta$-functions using a sequence of (non-supersymmetric) effective theories with heavy particles decoupled at the scale of their mass. We find that the difference between the SM couplings and their SUSY cousins that is ignored in the literature may be larger than two-loop effects which are included, and further that renormalization group evolution induces a non-trivial flavour structure in gaugino interactions. We present here the coupled set of RGEs for these dimensionless gauge and "Yukawa"-type couplings. The RGEs for the dimensionful SSB parameters of the MSSM will be presented in a companion paper.Comment: 67 pages, 5 figures, revtex4, bm.sty, amsmath.sty; Corrected Eqs. (59), (60) and (62) - (64). Results change by less than 0.05

Threshold and Flavour Effects in the Renormalization Group Equations of the MSSM II: Dimensionful couplings

We re-examine the one-loop renormalization group equations (RGEs) for the dimensionful parameters of the minimal supersymmetric Standard Model with broken supersymmetry, allowing for arbitrary flavour structure of the soft SUSY breaking (SSB) parameters. We include threshold effects by evaluating the $\beta$-functions in a sequence of (non-supersymmetric) effective theories with heavy particles decoupled at the scale of their mass. We present the most general form for high scale SSB parameters that obtains if we assume that the supersymmetry breaking mechanism does not introduce new inter-generational couplings. This form, possibly amended to allow additional sources of flavour-violation, serves as a boundary condition for solving the RGEs for the dimensionful MSSM parameters. We then present illustrative examples of numerical solutions to the RGEs. We find that in a SUSY GUT with the scale of SUSY scalars split from that of gauginos and higgsinos, the gaugino mass unification condition may be violated by ${\cal O}$(10%). As another illustration, we show that in mSUGRA, the rate for the flavour-violating $\tilde{t}_1\to c\tilde{Z}_1$ decay obtained using the complete RGE solution is smaller than that obtained using the commonly-used "single-step" integration of the RGEs by a factor 10-25, and so may qualitatively change expectations for topologies from top-squark pair production at colliders. Together with the RGEs for dimensionless couplings presented in a companion paper, the RGEs in Appendix B of this paper form a complete set of one-loop MSSM RGEs that include threshold and flavour-effects necessary for two-loop accuracy.Comment: 96 pages, 14 figures, revtex4, multirow.sty, bm.sty, amsmath.sty; Corrected Fig. 3 and Eqs. (B9), (B11), (B13) - (B20) and (B24). Results change by less than 1

Application of Bayesian model averaging to measurements of the primordial power spectrum

Cosmological parameter uncertainties are often stated assuming a particular model, neglecting the model uncertainty, even when Bayesian model selection is unable to identify a conclusive best model. Bayesian model averaging is a method for assessing parameter uncertainties in situations where there is also uncertainty in the underlying model. We apply model averaging to the estimation of the parameters associated with the primordial power spectra of curvature and tensor perturbations. We use CosmoNest and MultiNest to compute the model Evidences and posteriors, using cosmic microwave data from WMAP, ACBAR, BOOMERanG and CBI, plus large-scale structure data from the SDSS DR7. We find that the model-averaged 95% credible interval for the spectral index using all of the data is 0.940 < n_s < 1.000, where n_s is specified at a pivot scale 0.015 Mpc^{-1}. For the tensors model averaging can tighten the credible upper limit, depending on prior assumptions.Comment: 7 pages with 7 figures include

A Phospho-SIM in the Antiviral Protein PML is Required for Its Recruitment to HSV-1 Genomes

Herpes simplex virus type 1 (HSV-1) is a significant human pathogen that infects a large portion of the human population. Cells deploy a variety of defenses to limit the extent to which the virus can replicate. One such factor is the promyelocytic leukemia (PML) protein, the nucleating and organizing factor of nuclear domain 10 (ND10). PML responds to a number of stimuli and is implicated in intrinsic and innate cellular antiviral defenses against HSV-1. While the role of PML in a number of cellular pathways is controlled by post-translational modifications, the effects of phosphorylation on its antiviral activity toward HSV-1 have been largely unexplored. Consequently, we mapped phosphorylation sites on PML, mutated these and other known phosphorylation sites on PML isoform I (PML-I), and examined their effects on a number of PML’s activities. Our results show that phosphorylation at most sites on PML-I is dispensable for the formation of ND10s and colocalization between PML-I and the HSV-1 regulatory protein, ICP0, which antagonizes PML-I function. However, inhibiting phosphorylation at sites near the SUMO-interaction motif (SIM) of PML-I impairs its ability to respond to HSV-1 infection. Overall, our data suggest that PML phosphorylation regulates its antiviral activity against HSV-1

The impact of local authorities’ interventions on household waste collection: a case study approach using time series modelling

At a local Government level there have been many interventions and changes made to household waste collection services to meet new regulatory requirements. These changes include separate collection of recyclable and organic materials. This paper has used a time series model to quantify the success of interventions introduced by a LA. The case study was a medium sized UK LA, Charnwood Borough Council (CBC), the research analyses monthly data of quantities of recyclates, garden waste for composting and residual waste for landfill disposal. The time series model was validated with a five year data set and used to measure the impacts of the various changes to identify which intervention was the most successful, while controlling for season and number of working days. The results show the interventions analysed both had abrupt and permanent positive impacts on the yield of recyclable materials, and a corresponding negative impact on the residual waste. The model could be added to the National data base to help LAs to compare interventions and to understand which schemes encourage householder participation and improve recycling performance

Supraglacial forcing of subglacial drainage in the ablation zone of the Greenland ice sheet

Peer reviewedPublisher PD

Renormalisation Group Analysis of Supersymmetric Particle Interactions

In the Minimal Supersymmetric Standard Model (MSSM), there are numerous sources of flavour-violation in addition to the usual Kobayashi-Maskawa mixing matrix of the Standard Model. We reexamine the renormalisation group equations (RGEs) with a view to investigating flavour effects in a supersymmetric theory with an arbitrary flavour structure at some high scale. To incorporate (two-loop sized) threshold effects in the one-loop RGEs, we calculate the beta-functions using a sequence of (non-supersymmetric) effective theories with heavy particles decoupled at the scale of their mass, keeping track of the fact that many couplings (such as gauge and gaugino couplings) which are equal in an exact supersymmetric theory may no longer be equal once the supersymmetry (SUSY) is broken. We find that this splitting, which is ignored in the literature, may be larger than two-loop terms that are included. In addition, gaugino couplings develop flavour structure that is absent without including decoupling effects. A program (to be incorporated into ISAJET) has been developed, which includes flavour-violating couplings of superparticles and solves the two-loop threshold RGEs subject to specified high scale inputs. The weak scale flavour structure derived in this way can be applied to the study of flavour-changing decays of SUSY particles. As an illustration, we revisit the branching ratio of the flavour-violating decay of the top squark. We find that, in the minimal supergravity (mSUGRA) class of models, previous estimates for the width of this decay have been too large by a factor 10-25. We also analyse the consequences of introducing non-universality in the high scale soft SUSY-breaking mass matrices and find that under these conditions the partial width can be altered by a large amount.Comment: PhD Dissertation, approx. 212 pages, 22 figures, 5 table

In-Use Emissions Testing of Diesel-Driven Buses in Southampton:Is Selective Catalytic Reduction as Effective as Fleet Operators Think?

Despite the continuously tightening emissions legislation, urban concentrations of nitrogen oxides (NOx) remain at harmful levels. Road transport is responsible for a large fraction, wherein diesel engines are the principal culprits. Turbocharged diesel engines have long been preferred in heavy duty applications, due to their torque delivery and low fuel consumption. Fleet operators are under pressure to understand and control the emissions of their vehicles, yet the performance of emissions abatement technology in real-world driving is largely unquantified. The most popular NOx abatement technology for heavy duty diesel vehicles is selective catalytic reduction. In this work, we empirically determine the efficiency of a factory-fitted SCR system in realworld driving by instrumenting passenger buses with both a portable emissions measurement system (PEMS) and a custom built telematics unit to record key parameters from the vehicle diagnostics systems. Wefindthateveninrelativelyfavourableconditions, while there is some improvement due to the use of SCR, the vehicles operate far from the design emissions targets. The archival value of this paper is in quantification of real world emissions versus design levels and the factors responsible for the discrepancy, as well as in examination of technologies to reduce this difference